Hybrid level anharmonicity and interference induced photon blockade in a two-qubit cavity QED system with dipole-dipole interaction

TL;DR

This paper proposes a tunable photon blockade mechanism in a two-qubit cavity QED system with dipole-dipole interaction, combining energy-level anharmonicity and quantum destructive interference to enhance single-photon generation.

Contribution

It introduces a hybrid photon blockade scheme leveraging dipole-dipole interaction and quantum interference, improving control and efficiency over traditional methods.

Findings

Photon blockade depends on pump frequency with DDI present

Hybrid system enhances mean photon number and correlation

Photon blockade is tunable and experimentally feasible

Abstract

We theoretically study a quantum destructive interference (QDI) induced photon blockade in a two-qubit driven cavity QED system with dipole-dipole interaction (DDI). In the absence of dipole-dipole interaction, we show that a QDI-induced photon blockade can be achieved only when the qubit resonance frequency is different from the cavity mode frequency. When DDI is introduced the condition for this photon blockade is strongly dependent upon the pump field frequency, and yet is insensitive to the qubit-cavity coupling strength. Using this tunability feature we show that the conventional energy-level-anharmonicity-induced photon blockade and this DDI-based QDI-induced photon blockade can be combined together, resulting in a hybrid system with substantially improved mean photon number and second order correlation function. Our proposal provides a non-conventional and experimentally feasible platform for generating single photons.